Given the hierarchical nature of family structure, family systems theory places the interparental relationship as the cornerstone of the family unit (Cox & Paley, 2001). Although disagreements between parents are a regular and normal part of family life, entrenched, chronic, and hostile disputes are proposed to undermine family functioning. To understand how interparental conflict reverberates throughout the family system, process models of interparental discord have focused on identifying how interparental conflict ?spills over? to influence interactions within the parent? child system (Easterbrooks & Emde, 1988). Although a generation of research has been instrumental in cataloguing ?spillover? between the interparental and parent-child subsystems, little is known about the mechanisms underlying this relationship. The criticality of process-oriented research in this area is underscored by the high proportion of children who are exposed to interparental hostility and aggression (i.e., National Survey of Children's Health, 2003), with estimates suggesting that between 20% to 40% of parents who live together report significant, clinical levels of distress in their relationships (Cummings & Davies, 2010). Furthermore, experts place emphasis on the clinical value of identifying the etiology of parenting difficulties within high conflict homes (Emery, Fincham, & Cummings, 1992). As a first step toward advancing a process-oriented model of spillover the application addresses the following specific aims: (1) test a cascading family process whereby experiences with hostile interparental conflict increases parenting difficulties by undermining parental self-regulatory abilities; (2) examine whether parental neurobiological reactivity to interparental conflict mediates current and prospective associations among interparental conflict and parenting difficulties; (3) identify how parental explicit and implicit representations of the protective and supportive qualities of their intimate relationship may serve as explanatory processes underlying the spillover of distress from the interparental to parent-child relationship, and (4) consistent with calls underscoring the significance of understanding the relative role of mediational mechanisms in process models, specifically test the distinctiveness of each of the three pathways as mechanisms of spillover. To address these objectives, this application will follow a sample of 250 parents and their 3-4 year-old child over three annual measurement occasions. The multi-method, multi-informant, and multi-level measurement battery combined with powerful latent based quantitative approaches will generate authoritative tests of novel and theoretically guided hypotheses regarding the robustness of multi-level mechanisms underlying spillover from interparental relation dynamics to parenting.